Oil burner



June 19, S1928. 1,674,283

G. v. FLETCHER on. BURNER Filed March 21, 1927 2 sheets-sheet 2 Patented June v19, 192s.

.UNITED STATES- PATENT oFFlcE. e

GEORGE V. FLETCHER, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO HERBERT CLARK AND LESLIE W. PLACE, BOTH F MINNEAPOLIS, MINNESOTA, AND EARL MARR, OF PHILADELPHIA, PENNSYLVANIA. bi 4 OIL BURNER.

Application med-March 21, 1927.. serial No. 17e-,925'.

. My present invention relates to oil burners of the type wherein the vaporization of -tlie oil is produced by a violently whirling air current which sweeps up and evaporates the oil and rapidly forms a mixture suitable for complete combustion, and the invention is directed to highly important features which insure complete combustion by proper 'distribution of oil and the oil vapor and prevent carbon deposits. lAlso the invention comprises other important features, all as will hereinafter more fully appear.

A commercial form of burner is illustrated in the accompanying drawings wherein like characters indlcate like parts throughout the several views.-

Referring to the drawings: Fig. 1 is avertical section of the burner, some parts being broken away, some parts being shown in full and some parts being sectioned on the linel 1-1 of Fig. 2; i

Fig. 2 is a plan view of the burner shown in Fig. 1, the rim section of the bowl being removed; l l Fig. 3 is a bottom plan view of the parts shown in Fig. 2, s'ome parts being sectionedv onthe line 3 3 of Fig. 1; and

Fig. 4 is a transverse vertical section taken on vthe line 4-4 of Fig. 1.

The burner proper will of course be suit# ably 'connected within' a furnace, preferably with its bowl centrally located`l` in the plane usually occupied by the grate. In the device illustrated, the bowl 5 is set` partly into the casing 6 that constitutes an air trunk and is supported by suitable legs 7. As an inp'ortant feature of the invention, this casing 6 is provided with a large air intake pipe 8 which, in practice, will usually be connected to thel discharge pipe of the fan or blower. At its central portion the` casing 6 has a depressed cup 9, from the bottom of which an oil drain pipe 10 is extended.y The cup 9 is-formed with a sleeve 11 that extends upward from its bottom, is spaced from the walls ofthe cup to form an intervening oil chamber, and is terminated at its upper edge slightly above the bottom of said casing.-

A the bowl.

multiplicity of circumferentially spaced tangential au' ports 14 (as best""shown in Figs. 1 and 3) which perform a function presently to be noted. The bowl 5 sets on the rim of.

the casing 6 but at one side -is formed with a heavy llug-like portion 6" that is fitted closely intoy a notch formed in the adjacent portion oftherim of said-casing 6. This lug 6, at its lower portion,y is formed with a radial gas tip conduit 15 that leads to a gas burnertip 16 projected slightly into a pocket 17 formed in the inner portion of the lug portion 6a and opening directly into the auxiliary boit/1,13. Thiscup performs an im-A `lentu whirling motion over and just/above the bottom of the bowl. By reference particularly to Fig. 2 it will be noted that the'inner faces 18*v of the air ports 18 are oblique in respect to radial lines drawn from the axis of the bowl and that they deliver the air against curved deflecting surfacesA 19 which deflect the air toward the axis of the bowl and to the rim of the auxiliary bowl. One of the ports 18 is formed at least partly in the lug 6, and into the top of which-port opens a small oil duct 20. The oil supply pipe 21. which is screwed into the lug 6, de-

esVv

livers the oil into the duct 20; and a pilot y !Ias supply pipe 22, which is also screwed into said' lug 6, delivers Ato the gas conduit 15.

The body proper ofthe bowl 5 has an upwardflare but it is. desirable that the extreme upper portion of the bowl be contracted. Moreover. the extreme upper portion of the bowl will be subjected to very intense' head and will in service be given greater expansion and contraction than the bottom of Hence. this extreme upper portion of the bowl is made as `a separate element indicated at 23 and may even be of a different material'than the bowl. For example, the bowl proper may be' of cast iron while the detachable rim or upper portion on the upper or rim section 23 of the bowl is provided withY circumferentia ly spacedl vso is require and hence the bowl is provided with a converging ring flange 5al on which the detachable rim or upper portion is' loosely seated. The ring flange 5 as shown,

retainin lugs 24 that prevent the rim section 23 rom getting completely out of lace. The pipes 10, 21 and 22 all lead straig t toward the axis of the bowl so that they may be, without removal, readily cleaned out in case any carbon deposit should accumulate therein. l f Operation.

When air under pressurefrom thefan or4 blower is delivered into the air. trunk 6 it will be discharged through the ports 18 of the main bowl 5 and a lesser amount through the ports 14 of the auxiliary bowl 13. The delivery through the ports 18 and 14 will be tangential and hence the air willbe caused totake up rapid rotary motions within the respective bowls 5 and 13. The pilot light from the burner tip 16 will cause ignition of the vapor wit-hin the auxiliary bowl 13 and the flame discharged from the top thereof will be delivered through the bottom of the main bowl 5 and to the interior thereof under a rapid rotation and ofcourse with a vtrifuga force.l commingled with the va orsin the main tendenc to expand under the act-ion of cen- These burning gases will be bowl and the main com ustion will `take place within the main bowl wherein there will' be a lviolent and rapid rotation of the burning vapors.

It is now important to npte that the air blasts delivered from the ports 18V ofl the main bowl are directed slightly somewhat inward and toward the rim of the auxiliary bowl so that there will be a commingling of the two blasts. that is. whirling blasts from the auxiliary bowl will have to. cut their way` into each of the four streams of air from the ports 18 and all of the blasts from the ports 18 will be directed against a whirling blast from the auxiliary bowl.

Whirling vapors within the main lbowl .will of course'move quite rapidy upward but their discharge will be somewhat retared by therim section 23.- This will ,cause all or nearly all of the gases to be ignited within the bowl and b'e to allarge extent consumed' in the bowl before the unconsurned lvapors in the nature of flamewill be discharged from. the rim of the bowl under a lwhirling and expanding action, and the combustion will be completed close to the rim of the bowl and ofcourse within the fire box of the furnace. l

In experiments with burners of this general type but /without the auxiliary bowl at produce lcomplete combustlon or complete ignltion of gases .at the center of the bowl. yThis was 1 probably due to theformationof vacuum or dead air space at the axisofthe` bowl. In the operation of the device described, the auxiliary or preliminary whirling action of the gases within the auxiliary bowl was discharged into the main bowl at the axis there- 'of at the very place where hitherto there .carbon entirely eliminated.

had been incomplete combustion, due lto Y lthas also been found that the pilotfwas v more reliable when applied 'for action on the vapors within the relatively small box-like bowl for at this place therewas found-to be less tendency to blow out the pilot light. Moreover, this blowing of the pilot-.light was further guarded against by placing the pilot tip within a small pocket openingl into but offset from the auxiliary bowl.

In the .arrangement illustrated, vthe oil from the pipe 21 `is delivered through only one of the ports 18 and will be swept into the bowl only by the one blast but it will be instantly commmgled with the other blasts vand rapidly vaporized.

The numeral 25 indicates the overflow tube secured tov theI bottom of the auxiliary bowl 13, and extended-from a point above said bottom down into the sleeve 11 where it is terminated'above the bottom of the cup 9. The numeral 26 indicates a washer-like valve slidably mounted on the tube 25 and resting loosely on the'upper edge of the sleeve 11. This valve does not form a veryl tight joint with thesleeve 11 buttlwill prevent too great a flow of air from e trunk 6 upward through the tube 25.- n practice it has been found a slight flow of air from the ,i

trunk 6 up through the tube 25 such asjcan find its way through port 12 will not sto the flow of accumulated oil from the -auxi iary bowl 13 and out Vthrough the safety overflow pipe 10, but when too free a flow of air is permitted, such flow of accumulated oil will be stopped by the pressure of air, hence,

the use of `said valve 26. If the pilot light should go out and the su ply of o11 through pipe 21 and the supply o air-through pipe 8 should be continued 'it was found that the accumulated oill. in'bowl l3p-would notl ow under the action of gravity against the air blast out through the ports'14 and hence that the oil would accumulate' in the bowl 13 and bowl 5` and finally overflow from the latter. The introduction of the tube 26, however, pre- `vented `this accumulation and provided the safe overlow'for the accumulated oil which, running'frm the tube 25 out throu h pipe 10 totliecustomary valve cutofl mec amsm,

would cut othe supply of oil to supply pipe 21 and usuall at the same time Stop j the motor and the an.

air ports opening tangentiall main bowl, inward of its tangential ports,

l having deflect-ing surfaces for directing vthe air ports opening tangentially thereinto, a

air for combustion toward the rim of said auxiliary bowl. l

2. In an oil burner, a main bowl having relatively small auxiliar bowl depending from and opening central y throughlthebottom of said main bowl and having tangential air ports, means for supplying'iluid fuel to said burner, an air trunk Supplying air to the tangential air ports of said main and auxiliary bowls, and means for delivering air under pressure into said 'air trunk.

3. In an oil burner, a main bowl having air ports openin tangentially thereinto, of a relatively smal auxiliary bowl depending from and opening centrally through the bot.- tom of said main bowl and having tangential air orts, means for supplying fluid fuel to said urner, an air trun delivering air to the tangential air ports of lsaid main and auxiliary bowls, said air trunk having a depending cup formed with an internally spaced upstanding sleeve having a port near its bottom, an overflow tube extending through the bottom of said auxiliary bowl and into said sleeve, a valve mounted on said overflow tube and resting on the upper end of said sleeve, an 011 pi e extending to vsaid cup, and means for de ivering air un der pressure into said air trunk.

In testimongr whereof I aiiix my signature.

' EORGE V. FLETCHER. 

